<template>
  <div class="chart">
    <div class="chart-canvas" ref="chart" :style="{ height: height, width: width }" />
  </div>
</template>
<script>
// 引入 echarts 核心模块，核心模块提供了 echarts 使用必须要的接口。
import * as echarts from 'echarts/core';
// 引入柱状图, 折线图，散点图，饼图，盒须图表，图表后缀都为 Chart
import { BarChart, LineChart, PieChart, ScatterChart, BoxplotChart } from 'echarts/charts';
// 引入提示框，标题，直角坐标系组件，组件后缀都为 Component
import { TitleComponent, TooltipComponent, ToolboxComponent, LegendComponent, GridComponent } from 'echarts/components';
// 引入 Canvas 渲染器，注意引入 CanvasRenderer 或者 SVGRenderer 是必须的一步
import { CanvasRenderer } from 'echarts/renderers';
import { MarkLineComponent } from 'echarts/components';

// 注册必须的组件
echarts.use([
  TitleComponent,
  TooltipComponent,
  ToolboxComponent,
  LegendComponent,
  GridComponent,
  BarChart,
  LineChart,
  PieChart,
  ScatterChart,
  BoxplotChart,
  CanvasRenderer,
  MarkLineComponent
]);

export default {
  name: 'ChartView',
  props: {
    width: {
      type: String,
      default: '100%'
    },
    height: {
      type: String,
      default: '350px'
    },
    autoResize: {
      type: Boolean,
      default: true
    },
    chartOption: {
      type: Object,
      required: true
    },
    type: {
      type: String,
      default: 'canvas'
    }
  },
  data() {
    return {
      chart: null
    };
  },
  watch: {
    chartOption: {
      deep: true,
      handler(newVal) {
        if (this.chart) {
          this.clearChart();
        }
        this.initChart();
      }
    }
  },
  mounted() {
    if (this.chart) {
      this.clearChart();
    }
    this.initChart();
  },
  beforeDestroy() {},
  methods: {
    resizeHandler() {
      this.chart.resize();
    },
    initChart() {
      this.chart = echarts.init(this.$refs.chart, '', {
        renderer: this.type
      });
      this.chart.setOption(this.chartOption);
      window.addEventListener('resize', this.resizeHandler);
      this.chart.on('click', this.handleClick);
    },
    handleClick(params) {
      this.$emit('click', params);
    },
    clearChart() {
      this.chart.dispose();
      this.chart = null;
    }
  }
};
</script>
<style lang="scss">
.chart {
  width: 100%;
  height: 100%;
}
.chart-canvas {
  width: 100%;
}
</style>
